FA-62381 / Tax bracket computation / Open access
Head-of-household filers receive the married additional amount · case 01
An elderly head of household deducts 400 less than entitled.
ROOT CAUSE
The additional standard deduction is 1550 for every status.
VERIFIED REPAIR
Use 1950 per condition for single and head-of-household, 1550 for married statuses.
Unsuccessful approach: Treating only single filers as unmarried still shortchanges heads of household.
Case contract
solve(status, gross, earned, itemized, conditions, dependent, spouse_itemizes): stipulated deduction rules. Base standard deduction: single 14600, mfj 29200, mfs 14600, hoh 21900 (other statuses 'ERR:status'). A dependent's base is min(base, max(1300, earned + 450)). Then add 1950 per age/blindness condition for single or hoh, 1550 per condition for married statuses. If status is mfs and the spouse itemizes, the standard deduction is 0. The deduction is the larger of standard and itemized; taxable = max(0, gross - deduction). Return [deduction, taxable].
Why this case matters
Tax computations hinge on which slice, threshold, ordering and rounding rule applies at each step; a misplaced boundary silently misstates liabilities.
1 / The failure
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(status, gross, earned, itemized, conditions, dependent, spouse_itemizes):
std = {'single': 14600, 'mfj': 29200, 'mfs': 14600, 'hoh': 21900}
if status not in std: return 'ERR:status'
extra = 1550
base = std[status]
if dependent: base = min(base, max(1300, earned + 450))
s = base + extra * conditions
if status == 'mfs' and spouse_itemizes: s = 0
d = max(s, itemized)
return [d, max(0, gross - d)]
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
cases = [[('regression additional-amount-by-status 1', ('hoh', 30000, 30000, 0, 1, False, False), [23850, 6150]),
('regression additional-amount-by-status 2', ('single', 9000, 20000, 0, 1, True, False), [16550, 0]),
('partial repair guard 2', ('hoh', 53357, 900, 0, 2, False, False), [25800, 27557]),
('control: single standard', ('single', 50000, 50000, 0, 0, False, False), [14600, 35400]),
('control: dependent', ('single', 5000, 2000, 0, 0, True, False), [2450, 2550]),
('control: mfs spouse itemizes', ('mfs', 40000, 40000, 3000, 2, False, True), [3000, 37000]),
('control: mfj below deduction', ('mfj', 20000, 20000, 0, 2, False, False), [32300, 0])],
[('regression additional-amount-by-status 1', ('hoh', 53357, 900, 0, 2, False, False), [25800, 27557]),
('regression additional-amount-by-status 2', ('single', 45837, 500, 15000, 1, False, False), [16550, 29287]),
('partial repair guard 1', ('hoh', 22188, 500, 0, 1, True, True), [3250, 18938]),
('partial repair guard 2', ('hoh', 124688, 900, 0, 1, False, False), [23850, 100838]),
('control: mfs spouse itemizes', ('mfs', 40000, 40000, 3000, 2, False, True), [3000, 37000]),
('control: mfj below deduction', ('mfj', 20000, 20000, 0, 2, False, False), [32300, 0]),
('control: high-earning dependent', ('single', 9000, 20000, 0, 1, True, False), [16550, 0]),
('control: itemizer', ('mfj', 120000, 120000, 35000, 0, False, False), [35000, 85000])],
[('regression additional-amount-by-status 1', ('single', 111058, 500, 3000, 1, False, False), [16550, 94508]),
('regression additional-amount-by-status 2', ('hoh', 22188, 500, 0, 1, True, True), [3250, 18938]),
('partial repair guard 1', ('hoh', 72381, 20000, 25000, 2, False, True), [25800, 46581]),
('partial repair guard 2', ('hoh', 146977, 14000, 0, 2, False, False), [25800, 121177]),
('control: itemizer', ('mfj', 120000, 120000, 35000, 0, False, False), [35000, 85000]),
('control: bad status', ('widow', 1, 1, 0, 0, False, False), 'ERR:status'),
('control: dependent no earnings', ('single', 3000, 0, 0, 0, True, False), [1300, 1700]),
('control: single standard', ('single', 50000, 50000, 0, 0, False, False), [14600, 35400])],
[('regression additional-amount-by-status 1', ('single', 85478, 500, 0, 2, False, False), [18500, 66978]),
('regression additional-amount-by-status 2', ('hoh', 124688, 900, 0, 1, False, False), [23850, 100838]),
('partial repair guard 1', ('hoh', 39678, 500, 0, 1, True, True), [3250, 36428]),
('partial repair guard 2', ('hoh', 59881, 14101, 0, 1, False, False), [23850, 36031]),
('control: single standard', ('single', 50000, 50000, 0, 0, False, False), [14600, 35400]),
('control: hoh with age', ('hoh', 30000, 30000, 0, 1, False, False), [23850, 6150]),
('control: dependent', ('single', 5000, 2000, 0, 0, True, False), [2450, 2550]),
('control: mfs spouse itemizes', ('mfs', 40000, 40000, 3000, 2, False, True), [3000, 37000])],
[('regression additional-amount-by-status 1', ('hoh', 72381, 20000, 25000, 2, False, True), [25800, 46581]),
('regression additional-amount-by-status 2', ('single', 51379, 14000, 15000, 2, False, False), [18500, 32879]),
('partial repair guard 1', ('hoh', 124418, 2000, 3000, 2, False, False), [25800, 98618]),
('partial repair guard 2', ('hoh', 100490, 14000, 0, 2, False, False), [25800, 74690]),
('control: mfs spouse itemizes', ('mfs', 40000, 40000, 3000, 2, False, True), [3000, 37000]),
('control: mfj below deduction', ('mfj', 20000, 20000, 0, 2, False, False), [32300, 0]),
('control: high-earning dependent', ('single', 9000, 20000, 0, 1, True, False), [16550, 0]),
('control: itemizer', ('mfj', 120000, 120000, 35000, 0, False, False), [35000, 85000])]]
for label, args, expected in cases[N - 1]:
check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
| Boundary fixture | Actual | Expected | Outcome |
|---|---|---|---|
| regression additional-amount-by-status 1 | [23450, 6550] | [23850, 6150] | Failed |
| regression additional-amount-by-status 2 | [16150, 0] | [16550, 0] | Failed |
| partial repair guard 2 | [25000, 28357] | [25800, 27557] | Failed |
| control: single standard | [14600, 35400] | [14600, 35400] | Passed |
| control: dependent | [2450, 2550] | [2450, 2550] | Passed |
| control: mfs spouse itemizes | [3000, 37000] | [3000, 37000] | Passed |
| control: mfj below deduction | [32300, 0] | [32300, 0] | Passed |
SHA-256 / 0fe27e487ddcb5cc5aa530bacaf418dc435eaa3cbe67a4b930b21ddfcb809d5b
2 / The unsuccessful fix
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(status, gross, earned, itemized, conditions, dependent, spouse_itemizes):
std = {'single': 14600, 'mfj': 29200, 'mfs': 14600, 'hoh': 21900}
if status not in std: return 'ERR:status'
extra = 1950 if status == 'single' else 1550
base = std[status]
if dependent: base = min(base, max(1300, earned + 450))
s = base + extra * conditions
if status == 'mfs' and spouse_itemizes: s = 0
d = max(s, itemized)
return [d, max(0, gross - d)]
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
cases = [[('regression additional-amount-by-status 1', ('hoh', 30000, 30000, 0, 1, False, False), [23850, 6150]),
('regression additional-amount-by-status 2', ('single', 9000, 20000, 0, 1, True, False), [16550, 0]),
('partial repair guard 2', ('hoh', 53357, 900, 0, 2, False, False), [25800, 27557]),
('control: single standard', ('single', 50000, 50000, 0, 0, False, False), [14600, 35400]),
('control: dependent', ('single', 5000, 2000, 0, 0, True, False), [2450, 2550]),
('control: mfs spouse itemizes', ('mfs', 40000, 40000, 3000, 2, False, True), [3000, 37000]),
('control: mfj below deduction', ('mfj', 20000, 20000, 0, 2, False, False), [32300, 0])],
[('regression additional-amount-by-status 1', ('hoh', 53357, 900, 0, 2, False, False), [25800, 27557]),
('regression additional-amount-by-status 2', ('single', 45837, 500, 15000, 1, False, False), [16550, 29287]),
('partial repair guard 1', ('hoh', 22188, 500, 0, 1, True, True), [3250, 18938]),
('partial repair guard 2', ('hoh', 124688, 900, 0, 1, False, False), [23850, 100838]),
('control: mfs spouse itemizes', ('mfs', 40000, 40000, 3000, 2, False, True), [3000, 37000]),
('control: mfj below deduction', ('mfj', 20000, 20000, 0, 2, False, False), [32300, 0]),
('control: high-earning dependent', ('single', 9000, 20000, 0, 1, True, False), [16550, 0]),
('control: itemizer', ('mfj', 120000, 120000, 35000, 0, False, False), [35000, 85000])],
[('regression additional-amount-by-status 1', ('single', 111058, 500, 3000, 1, False, False), [16550, 94508]),
('regression additional-amount-by-status 2', ('hoh', 22188, 500, 0, 1, True, True), [3250, 18938]),
('partial repair guard 1', ('hoh', 72381, 20000, 25000, 2, False, True), [25800, 46581]),
('partial repair guard 2', ('hoh', 146977, 14000, 0, 2, False, False), [25800, 121177]),
('control: itemizer', ('mfj', 120000, 120000, 35000, 0, False, False), [35000, 85000]),
('control: bad status', ('widow', 1, 1, 0, 0, False, False), 'ERR:status'),
('control: dependent no earnings', ('single', 3000, 0, 0, 0, True, False), [1300, 1700]),
('control: single standard', ('single', 50000, 50000, 0, 0, False, False), [14600, 35400])],
[('regression additional-amount-by-status 1', ('single', 85478, 500, 0, 2, False, False), [18500, 66978]),
('regression additional-amount-by-status 2', ('hoh', 124688, 900, 0, 1, False, False), [23850, 100838]),
('partial repair guard 1', ('hoh', 39678, 500, 0, 1, True, True), [3250, 36428]),
('partial repair guard 2', ('hoh', 59881, 14101, 0, 1, False, False), [23850, 36031]),
('control: single standard', ('single', 50000, 50000, 0, 0, False, False), [14600, 35400]),
('control: hoh with age', ('hoh', 30000, 30000, 0, 1, False, False), [23850, 6150]),
('control: dependent', ('single', 5000, 2000, 0, 0, True, False), [2450, 2550]),
('control: mfs spouse itemizes', ('mfs', 40000, 40000, 3000, 2, False, True), [3000, 37000])],
[('regression additional-amount-by-status 1', ('hoh', 72381, 20000, 25000, 2, False, True), [25800, 46581]),
('regression additional-amount-by-status 2', ('single', 51379, 14000, 15000, 2, False, False), [18500, 32879]),
('partial repair guard 1', ('hoh', 124418, 2000, 3000, 2, False, False), [25800, 98618]),
('partial repair guard 2', ('hoh', 100490, 14000, 0, 2, False, False), [25800, 74690]),
('control: mfs spouse itemizes', ('mfs', 40000, 40000, 3000, 2, False, True), [3000, 37000]),
('control: mfj below deduction', ('mfj', 20000, 20000, 0, 2, False, False), [32300, 0]),
('control: high-earning dependent', ('single', 9000, 20000, 0, 1, True, False), [16550, 0]),
('control: itemizer', ('mfj', 120000, 120000, 35000, 0, False, False), [35000, 85000])]]
for label, args, expected in cases[N - 1]:
check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
| Boundary fixture | Actual | Expected | Outcome |
|---|---|---|---|
| regression additional-amount-by-status 1 | [23450, 6550] | [23850, 6150] | Failed |
| regression additional-amount-by-status 2 | [16550, 0] | [16550, 0] | Passed |
| partial repair guard 2 | [25000, 28357] | [25800, 27557] | Failed |
| control: single standard | [14600, 35400] | [14600, 35400] | Passed |
| control: dependent | [2450, 2550] | [2450, 2550] | Passed |
| control: mfs spouse itemizes | [3000, 37000] | [3000, 37000] | Passed |
| control: mfj below deduction | [32300, 0] | [32300, 0] | Passed |
SHA-256 / 0e92759ad5f438637a687a60f258e88e891884ef1b618f61c7c060b905816fa2
3 / The verified repair
Exit 0"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(status, gross, earned, itemized, conditions, dependent, spouse_itemizes):
std = {'single': 14600, 'mfj': 29200, 'mfs': 14600, 'hoh': 21900}
if status not in std: return 'ERR:status'
extra = 1950 if status in ('single', 'hoh') else 1550
base = std[status]
if dependent: base = min(base, max(1300, earned + 450))
s = base + extra * conditions
if status == 'mfs' and spouse_itemizes: s = 0
d = max(s, itemized)
return [d, max(0, gross - d)]
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
cases = [[('regression additional-amount-by-status 1', ('hoh', 30000, 30000, 0, 1, False, False), [23850, 6150]),
('regression additional-amount-by-status 2', ('single', 9000, 20000, 0, 1, True, False), [16550, 0]),
('partial repair guard 2', ('hoh', 53357, 900, 0, 2, False, False), [25800, 27557]),
('control: single standard', ('single', 50000, 50000, 0, 0, False, False), [14600, 35400]),
('control: dependent', ('single', 5000, 2000, 0, 0, True, False), [2450, 2550]),
('control: mfs spouse itemizes', ('mfs', 40000, 40000, 3000, 2, False, True), [3000, 37000]),
('control: mfj below deduction', ('mfj', 20000, 20000, 0, 2, False, False), [32300, 0])],
[('regression additional-amount-by-status 1', ('hoh', 53357, 900, 0, 2, False, False), [25800, 27557]),
('regression additional-amount-by-status 2', ('single', 45837, 500, 15000, 1, False, False), [16550, 29287]),
('partial repair guard 1', ('hoh', 22188, 500, 0, 1, True, True), [3250, 18938]),
('partial repair guard 2', ('hoh', 124688, 900, 0, 1, False, False), [23850, 100838]),
('control: mfs spouse itemizes', ('mfs', 40000, 40000, 3000, 2, False, True), [3000, 37000]),
('control: mfj below deduction', ('mfj', 20000, 20000, 0, 2, False, False), [32300, 0]),
('control: high-earning dependent', ('single', 9000, 20000, 0, 1, True, False), [16550, 0]),
('control: itemizer', ('mfj', 120000, 120000, 35000, 0, False, False), [35000, 85000])],
[('regression additional-amount-by-status 1', ('single', 111058, 500, 3000, 1, False, False), [16550, 94508]),
('regression additional-amount-by-status 2', ('hoh', 22188, 500, 0, 1, True, True), [3250, 18938]),
('partial repair guard 1', ('hoh', 72381, 20000, 25000, 2, False, True), [25800, 46581]),
('partial repair guard 2', ('hoh', 146977, 14000, 0, 2, False, False), [25800, 121177]),
('control: itemizer', ('mfj', 120000, 120000, 35000, 0, False, False), [35000, 85000]),
('control: bad status', ('widow', 1, 1, 0, 0, False, False), 'ERR:status'),
('control: dependent no earnings', ('single', 3000, 0, 0, 0, True, False), [1300, 1700]),
('control: single standard', ('single', 50000, 50000, 0, 0, False, False), [14600, 35400])],
[('regression additional-amount-by-status 1', ('single', 85478, 500, 0, 2, False, False), [18500, 66978]),
('regression additional-amount-by-status 2', ('hoh', 124688, 900, 0, 1, False, False), [23850, 100838]),
('partial repair guard 1', ('hoh', 39678, 500, 0, 1, True, True), [3250, 36428]),
('partial repair guard 2', ('hoh', 59881, 14101, 0, 1, False, False), [23850, 36031]),
('control: single standard', ('single', 50000, 50000, 0, 0, False, False), [14600, 35400]),
('control: hoh with age', ('hoh', 30000, 30000, 0, 1, False, False), [23850, 6150]),
('control: dependent', ('single', 5000, 2000, 0, 0, True, False), [2450, 2550]),
('control: mfs spouse itemizes', ('mfs', 40000, 40000, 3000, 2, False, True), [3000, 37000])],
[('regression additional-amount-by-status 1', ('hoh', 72381, 20000, 25000, 2, False, True), [25800, 46581]),
('regression additional-amount-by-status 2', ('single', 51379, 14000, 15000, 2, False, False), [18500, 32879]),
('partial repair guard 1', ('hoh', 124418, 2000, 3000, 2, False, False), [25800, 98618]),
('partial repair guard 2', ('hoh', 100490, 14000, 0, 2, False, False), [25800, 74690]),
('control: mfs spouse itemizes', ('mfs', 40000, 40000, 3000, 2, False, True), [3000, 37000]),
('control: mfj below deduction', ('mfj', 20000, 20000, 0, 2, False, False), [32300, 0]),
('control: high-earning dependent', ('single', 9000, 20000, 0, 1, True, False), [16550, 0]),
('control: itemizer', ('mfj', 120000, 120000, 35000, 0, False, False), [35000, 85000])]]
for label, args, expected in cases[N - 1]:
check(label, solve(*args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
| Boundary fixture | Actual | Expected | Outcome |
|---|---|---|---|
| regression additional-amount-by-status 1 | [23850, 6150] | [23850, 6150] | Passed |
| regression additional-amount-by-status 2 | [16550, 0] | [16550, 0] | Passed |
| partial repair guard 2 | [25800, 27557] | [25800, 27557] | Passed |
| control: single standard | [14600, 35400] | [14600, 35400] | Passed |
| control: dependent | [2450, 2550] | [2450, 2550] | Passed |
| control: mfs spouse itemizes | [3000, 37000] | [3000, 37000] | Passed |
| control: mfj below deduction | [32300, 0] | [32300, 0] | Passed |
SHA-256 / f4a2c0489e8397852b28d9524035f06681f5fcc99f37f5490167779dbaf5932f
Verification & scope
A deterministic, bounded teaching model with a stipulated toy contract; it makes no claim of conformance to any real regulation, standard, or institution's rules. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.
Observations recorded using Python 3.12.14 at 2026-09-29T14:47:04.057705+00:00.
Case digest / fe518f988570f10cccf3772d1c59b8a74b6f4ffbbd4ef889882d25283cff7e63